Through the years, the leagues have become more similar in rules and style, though the NL maintains a different style of play from the AL by continuing to eschew the designated hitter rule. The NL's style is a game that is less big-offense driven. The difference, arguably, was never so obvious as during the 1970s and 1980s. In 1997, teams in the National League began to play a number of interleague games against American League opponents each season.

Also in 1997, Radical Realignment almost saw seven NL teams switch to the American League. The plan failed and the NL kept all the teams, as well as gaining the Milwaukee Brewers from the AL. From 1998 to 2012, the National League had 16 teams while the American had 14; the two leagues had the same number of teams - 15- starting in 2013, after the Houston Astros switched to the AL.

Also, during that time, many teams played in multi-purpose stadiums that doubled as football stadiums. These stadiums often had playing surfaces made of artificial turf - "Astroturf" - rather than natural grass. By 2005, however, every NL team had eliminated artificial turf in favor of natural grass.

The office was eliminated in 1999, although Bill Giles, son of former National League President Warren Giles, and current Phillies Chairman, currently holds the title of honorary National League president.